bugGNU Octave - Bugs: bug #34185, LUINC: pivot matrix output is a...

 
 

bug #34185: LUINC: pivot matrix output is a vector

Submitted by:  None
Submitted on:  Wed 31 Aug 2011 11:26:42 PM UTC  
 
Category: LibrariesSeverity: 3 - Normal
Priority: 5 - NormalItem Group: Matlab Compatibility
Status: FixedAssigned to: None
Originator Name: UMCPOriginator Email: -unavailable-
Open/Closed: ClosedRelease: 3.4.2
Operating System: GNU/Linux

Add a New Comment(Rich Markup)
   

You are not logged in

Please log in, so followups can be emailed to you.

 

Fri 02 Sep 2011 01:34:55 AM UTC, comment #2:

I've pushed this changeset:

http://hg.savannah.gnu.org/hgweb/octave/rev/8afb81b32748

I didn't realise the first time around that the behaviour depended on reading uninitialised memory. I also made the matrices p and q permutation matrices for consistency with lu().

Jordi GutiƩrrez Hermoso <jordigh>
Project Administrator
Thu 01 Sep 2011 10:02:44 PM UTC, comment #1:

This is a trivial fix. The option which controls 'vector' was not initialized to false at the start of the function. However, because the input for luinc is sparse the output for P is not of type "permutation matrix" but of type "sparse". The output from your example is

This still seems like the right fix since if users want a matrix as a return argument they should get it, even if it looks a little strange because of the Sparse encoding.

Rik <rik5>
Project Administrator
Wed 31 Aug 2011 11:26:42 PM UTC, original submission:

The pivot matrix outputted by LUINC is a vector even without specifying the optional 'vector' input argument. It should be a matrix (LU is okay). This affects Octave 3.2.4 and 3.4.2. Example:

octave-> [ail aiu aip] = luinc(sparse([1 2 ; 7 9]), 1e-3)
...
aip =

2
1

versus:

octave-> [ail aiu aip] = lu([1 2 ; 7 9])
...
aip =

Permutation Matrix

0 1
1 0

Anonymous

 

(Note: upload size limit is set to 16384 kB, after insertion of the required escape characters.)

Attach File(s):
   
   
Comment:
   

No files currently attached

 

Depends on the following items: None found

Items that depend on this one: None found

 

Carbon-Copy List
  • -unavailable- added by jordigh (Posted a comment)
  • -unavailable- added by rik5 (Posted a comment)
  •  

    Do you think this task is very important?
    If so, you can click here to add your encouragement to it.
    This task has 0 encouragements so far.

    Only project members can vote.

     

    Please enter the title of George Orwell's famous dystopian book (it's a date):

     

     

    Follow 3 latest changes.

    Date Changed By Updated Field Previous Value => Replaced By
    Fri 02 Sep 2011 01:34:55 AM UTCjordighStatusConfirmed=>Fixed
      Open/ClosedOpen=>Closed
    Thu 01 Sep 2011 10:02:44 PM UTCrik5StatusNone=>Confirmed

    Back to the top


    Powered by Savane 3.1-cleanup1